1. Who invented Automatic rifle ?

Answer: John Browning of U.S.A. in 1918.

2. Who invented by Electric Lamp ?

Answer: Thomas Alva Edison of U.S.A. in 1879

3. Who invented Relativity Theory ?

Answer: Einstein of Germany in 1905.

4. Who invented paper ?

Answer:

Cai Lun

5. Who invented Hydrogen bomb ?

Answer:

Edward Teller

6. Who invented Printing Press ?

Answer:

Johannes Gutenberg

7. Who invented Stethoscope ?

Answer: Laennec of French in 1819.